156 LIFE OF
represented, and developed them from his former
themes, on the footing of continual progress.
This is the exterior history of that groat work,
which has appeared in modern times under the
title " Kosmos."
But this work has also an inner history which
reflects the mental development of Humboldt\s life.
"We have called this work a testament, a, heritage to
the world, and Humboldt himself says of it tlutt lio
offers a work to the German public in the evening of
his active life, the plan for which has been present to
his sotil in faint outline for nearly half a coniuiry.
He recognised the importance of his scientific testa-
ment, for he knew that he must conclude the results
of his life. He often deemed the undertaking; impracti-
cable, and yet, xirged by the collective fruits of luslife?
and by the feeling that he owed the world a general
resum^ of his researches, extended over a period of
fifty years, he always returned to this work of making
the treasures of his eminent mind the common pro-
perty of his Gorman fatherland, and to delegate it to
them as a valuable inheritance. This feeling is
expressed by the fact that he wrote the work in the
German language. The great purpose of his life was
to comprehend all matter in its general connexion
and entire nature as a unity, moved and impregnated
by inner powers. By the investigation of a single
fact in natural science, %he knowledge of other single
facts were revealed to him, for the different domains
of science fertilized each other ; he explained the
complicated causes of the varied forms of existence,
and traced them to the prevailing laws of the unity
This great aim of his life was especially advanced by
the happiest social circumstances which are ratoly
offered to a scientific traveller ; for ho not only found
the opportunity of seeing coast lands, like most
circumnavigators, but also of penetrating far into
interior plains of two world-quarters, where lie inves-
tigated the most prominent contrasts of nature,—tho